An Economic Analysis of Unauthorized Copying on the Internet

1）我们考虑最简单的DRM，它允许免费或不允许复制，并且有关消费者类型的信息不完整。我们首先获得一般情况下消费者可分离性的结果，并表明存在关键类型的消费者。较高的实用类型选择自由复制菜单，而较低的实用类型则选择不复制。在两类模型中，我们表明生产者的最优定价与两部分关税下的最优定价不同。当且仅当自我生产比生产者的生产效率更高时，这种价格策略才能带来更大的利润和社会福利。2）尽管生产者试图保护其内容免受互联网上的版权侵犯，但这并不容易，就像防止非法停车一样。对于这种情况，他们不仅要考虑版权保护，还要考虑这种未经授权的文件共享对交易成本的影响。我们考虑复制控制是否有效，以减少对生产者利润的损害并增加社会福利。由于复制控制使得复制在物理上变得不可能，因此与没有复制控制的情况相比，它降低了消费者的利益。我们表明，未经授权的文件共享的交易成本决定了复制控制的有效性，并获得了生产者有动机引入复制控制的条件，同时与社会角度的激励相兼容。

1)We considers the simplest DRM, which permits either free or no copying, with incomplete information about the type of consumer. We first obtain results concerning separability of consumers in a general situation, and show that there is a critical type of consumer. A higher utility type selects a menu of free copying whereas a lower one chooses not to copy. In a two-type model we indicate that optimal pricing for a producer is different from that under two-part tariffs. This price strategy brings about greater profits and social welfare if, and only if, self production is more efficient than that of a producer.2)Although producers seek to protect their content from copyright infringement on the Internet, it is not easy, being similar to preventing illegal parking. For such a situation, they must not only consider copyright protection, but also the effect on transaction costs from such unauthorized file-sharing. We consider whether copy control is effective in order to reduce damages to the producer's profits and to increase social welfare. Since copy control makes copying physically impossible, it decreases consumer benefits, compared with those from no copy control. We show that transaction costs of unauthorized file-sharing determine the effectiveness of copy control and obtain the conditions under which there is an incentive for a producer to introduce copy control while being compatible with an incentive from a social perspective.